Five years of funding are sought to pursue translational research on the externalizing spectrum of personality and psychopathology. The externalizing spectrum is conceived of as a coherent set of personality traits and psychopathological syndromes characterized by a lack of impulse control. At the highest level within this spectrum stands a variable that links specific externalizing disorders and traits, the externalizing dimension. Recent research demonstrates both the existence and high heritability of this dimension via significant observed (phenotypic) and etiological (genetic) connections between an unconstrained, impulse-driven personality style and psychopathological syndromes involving antisocial behavior and substance dependence. This application seeks to build on these preliminary data by pursuing three specific aims. First, quantitative models of behaviors in the externalizing spectrum will be built by developing a hierarchical model of the externalizing spectrum that links the broad externalizing dimension to its manifestations as specific traits and syndromes. Second, models of externalizing behavior will be linked to models of neurocognitive processing, with a particular focus on event related potentials, to characterize the biobehavioral bases of externalizing behavior. Third, high levels of externalizing will be studied in criminal offender samples to characterize the implications of the externalizing spectrum model for understanding behaviors with high social costs, such as reactive violence and impulsive suicide attempts. This research is designed to realize the aims of the RFA to which it is a response by integrating ideas from diverse scientific areas (ranging from statistical modeling to cognitive neuroscience), in linking basic methodological advances in these areas to a broad range of costly, impulsive behaviors in both clinical and non-clinical samples.